The present invention relates to a voltage controlled oscillator (VCO) incorporated entirely on a single semiconductor chip.
Voltage controlled oscillators generally incorporate two major components, an oscillating device, and a means for tuning the frequency of the oscillating device when an applied voltage is varied. These two major components and other related components are typically individual parts, although they might be interconnected to form a relatively compact package. For example, the oscillating device can be an FET which produces an effective negative resistance at radio or microwave frequencies, and the tuning device can be a varactor diode which changes capacitance as a function of a voltage applied thereto.
Problems are encountered, however, when conventional VCOs are operated at high frequencies, such as in the radio or microwave range. At high frequencies, the interconnections between the VCO components create parasitic reactances which are detrimental to VCO performance. If the number and size of interconnections between components could be reduced it is expected that superior bandwidth, output power, operating frequency, and efficiency could be achieved.